Electric-circuit thermostat



J. H. DERBY AND E. S. CLAYTON.

ELECTRIC CIRCUIT THERMOSTAT.

APPLICATION man nEc.5, 1911.

Patented July 27, 1920.

UNITED STATES PATENT omer..

JOHN H. V:DERBY .AlN'ZD ERNEST S. CLAYTON, OF NEW YORK, N. Y.,ASSAIGNOBS TO l AMERICAN FIRE PREVENTION' BUREAU, INC., A` CORPORATIONOF NEW YORK.

ELECTRIC-CIRCUIT THERMOSTAT.

Specification of Letters Patent.

`Patenaai July 27, 1920'.

Applicationjiled December 5, 1917. Serial No. 205,524.

To all whom it may concern:

Be it known that we, JOHN H. DERBY .and ERNEST S. CLAYTON, citizens ofthe United States, residing at New York city, N. Y., have inventedcertain new and usefull, and exact description. 0 U

This invention relates to anl electric c1rcuit thermostat, andparticularly of the type.,l

operated by the influence of any unusual temperature, such as might bedue to a fire, to close an electriccircuit and give a fire alarm signal.

One object of the present invention is to provide an easily and cheaplymanufactured product of few parts and of simple construction, which canbe rolled together into lengths of any desired extent for installationin a building or other area which it is desired to' protect againstfire.

A further, object is to safely insulate the parts of the circuit fromone another under all conditions except the presence of heat, and toprotect the short cireuiting lmeans for said circuit against theintrusion of moisture, dirt, or other foreign material, whereby saidthermostat may be left 1n exposed condition for long periods of timewithout deterioration, and yet be ready for instant service when calledupon for operation. y

A further object of the invention-is to provide a visible signal atvariousl points along the line of the thermostat so as to indicate wherethe same has operated.

Various other objects and advantages of the invention will becomeapparent from the following description when taken in connection withthe accompanying drawings, which describe and show the preferredembodiment of the invention, and in which-' Figure 1' is a plan viewfrom the underside of a length of the complete thermostat; Fig. 2 is across-section of the same along line 2--2 of Fig. 1; l

Fig. 3 is a group view of the several parts of the thermostat detachedand in tive; and l.

Fig. 4 is a sectional view of a modification. .Referring'moreparticularly to the `drawings, l indicates a base strip of someelectrical conducting material fusible at a comparatively hightemperature, preferably phosphor bronze, so as to serve as a goodsulating sleeve 9 are series of perforations,

perspecconductor` for an electric circuit, and rolled in channeled formto rovide a thin-fiat bottom wall and abrupt y upturned side walls 2with laterally extending flanges 3. As shown in Fi 1, the bottom wall ofsaid channel 1 is ormed at intervals there along with transversecorrugations 4.- andl miniature openings 5 therethrough, the purpose ofwhich will be later described.

7 indicates a strip of easilyfusible solder that is fusible at acomparatively low temperature, and which is adapted to melt in thepresence of any unusual degree of heat,

such as might be produced by a fire .in the vicinity thereof. As shown,the strip of solder 7 is co-extensive with the channel member 1 and inclose contact with the bottom wallthereof, with its edges confinedbetween the side walls 2. The solder strip is also preferably formedwith transverse phosphor bronze, to serve asmaA second conductor,indicated at 8, and completely surrounded by a sleeve of iexibleinsulating material such as'varnished silk, indicated at 9. At intervalsalong the 'length of the insuch as 10, through which the fusible solder5 is adapted to spread when melted, to form an electrical connectionbetween the channel conducting member 1 and the strip 8. An additionalcover strip 10a is provided above the insulatedconducting strip 8 asshown, and` said vcover strip -10a likewise has lateral flanges 11',which are interlocked in any suitable manner with thalianges 3 95 ofth'e base member 1, to firmly clamp the parts together and form a closedcontinuous length c asin for the insulated conductor 8 and they s ortcircuiting solder strip 7. The interlocked flanges 3 and 11 -are pro-100 vided with bolt holes preferably in Staggered relation, whereby saidcasing may be attached to asupport such as a ceiling or f. wall of aroom.

It will be noted also that the cover strip 105 10EL is preferably archeddownwardly at its central portion to `firmly press the parts within thecasing against the bottom wall of the channel member 1, to therebyfacilitate the spreading of the solder through the per- 110 corrugationsat intervals interfitting with forations of the silk sleeve whenmelted.`

The corrugations 4, upon the channel Inemining side Walls 2 prevent theVlaterall v spreading f the solder, thus forcing the solder, whenmelted, to spread upwardly through the perforations of the silk sleeve 9into bridging contact with the second conductor 8. rlhe corrugations 4are preferably impressed on said member l, and the solder stripsimultaneously by passing the same to get-her through corrugating rolls,previous to the complete assembling of the parts.

The miniature holes .5 furnish openings through which a small portion ofthe solder will bulge, when melted, to indicate which part of thethermostat has operated.

rlhe channel member l may be connected to' one wire l2 of an electriccircuit and thc conductor 8 tothe other wire 13 of said circuit, and itwill be obvious that upon the melting of any portion of the solder 7 theconductors l and"8 are short circuited so that any suitable electricsignal may be given at a distant station. it Will'also be observed thatthe thermostat can be manufactured by the simple process of rollingseveral iiat strips together into any length desired, and that it maybestrung about a building with even less cost than ordinary electricwiring, as it provides its own; attaching meansand its own insulation.

In the modification shown in Fig. 4L, the conducting strip 8 isdispensed with and the cover l0aN is employed as one element of theconducting circuit, and the channel member 1, as before, is employed asthe other conducting member of the circuit. The insulating sheet ofvarnished silk 9 is laid above the solder strip 7 and its side portions9 are extended laterally and co-extensively with the side portions 1l ofthe cover strip l0a and are turned together with the anges l1 of thecover strip around the edges of the channel strip l, the varnished silksheet 9 thus`completely insulating the cover strip 10a 'from the channelstrip l. In order to secure this modified form of device to a support,additional clips such as 2O are preferably employed, having ordinaryscrews 21 for fastening the same and adapted to engage the iianges ofthe thermostatic device, as shown, to support the same in position.

lVhile we have shown and described wha .A

tion as claimed.

'intervals V'lengthwise spreading of said fusible ma- That we claim asnew isl. In an electric circuit thermostat, cornprising a continuouslength casing, said casing including within its area side walls andseparated conductors for an electric circuit normally insulated from oneanother by a strip of insulating material having perforationstherethrough, a thin flat strip of easily fusible conductingmaterialiconfined between said side walls and adapted, when fused, tospread through said perforations, and electrically bridge said circuitconductors, said strip of said insulating material and strip of easilyfusible conducting material being coextensive with said casing.

2. An electric circuit thermostat of con tinuousl length having a thinfiat bottom wall forming a conductor and abruptly upturned side walls, asecond conductor normally insulated from said bottom wall by acontinuous strip of insulating material having perforationstherethrough, a thin fiat strip of easily fusible conducting materialcoeXtensive with said bottom wall and with its lateral edges confinedbetween said side walls and adapted, when fused, to spread through saidperforations and electrically bridge said circuit conductors. .Y

` 3. An electric circuit thermostat of continuous length having a thinfiat bottom wall forming. a conductor and abruptly upturned side walls,a second conductor normally insulated from said bottom wall by acontinuous strip of insulating material having perforations therethroughat intervals therealong, a thin flat strip of easily fusible conductingmaterial co-eXtensive virith said bottom wall and,vv confined betweensaid side walls and adapted, when fused, to spread through saidperforations and electrically bridge said circuit conductors.

4. An electric circuit thermostat of continuous length having a thinflat bottom wall forming a conductor and abruptly upturned side walls,"asecond conductor normally insulated from said bottom wall by acontinuous strip of insulating material having perforationstherethrough, a thin flat strip of easily fusible conducting materialcoeXtensive with said bottom wall and with its lateral edges confinedbetween said side walls and adapted, when fused, to spread through saidperforations and electrically bridge said circuit conductors, saidbottom wallhaving raised surfaces transversely thereof and at along itslength to retard the terial when melted.

5,'An electric circuit thermostat of con- Vtinuous length having a thinflat bottom wall forming a conductor and abruptly upturned side walls, asecondv conductor normally insulated fromA Said bottom wall by acontinuous strip of insulating material having perforationstherethrough, a thin'fiat strip Lampes co-extensive fusible strip havinginterfitting corrugations transversely thereof at lnter-` valstherealong to retard the lengthwise spreading of said fusible materialwhen melted.

6. An electric circuit thermostat, comprising a channeled strip havingan electrically conducting portion and a cover strip fastened togetherto form a continuous length casing, a second conductor normallyinsulated from the electrically conducting portion of said channeledstrip'by a continuous' strip of insulating material having perforationstherethrough, a thinfiiat strip of easily fusible conducting materialco-extensive With said channeledl strip, and conined v vithin saidchanneled portion and adapted, When fused, to spread through saidperforations .and electrically bridge said circuit conductors.

7. An electric circuitthermostat, comprising va channeled strip havingan electrically conducting portion and a cover strip with interlockinglateral flanges forming a continuous length casing, a second conductornormally insulated from the electrically conducting portion of saidchanneled strip by a continuous strip of insulating material havingperforations Itherethrough, a-l thin flat strip of easily fusibleconducting material co-extensive with said channeled strip, and confinedWithin said channeled portion and adapted, When fused, to spread throughsaid perforations and electrically bridge said circuit conductors.

8. An electric circuit thermostat, 'comprising a continuous lengthcasing having a thin flat bottom Wall and abruptly upturned side Wallsof comparatively high temperature fusing'material and serving as aconductor for an electric circuit, a thin `flat strip of comparativelylovv` temperature fusing conducting material lying length- Wise of saidlbottom wall in contact therewith and With its lateral edges confinedbetween said side walls, a second thin Hat y Strip of comparatively hightemperature fusingconducting material surrounded by a sleeve ofinsulating material and lylng above said low fusible'strip, saidinsulating sleeve having perforations therethrou h on the side facingsaid low temperature usin strip, said low temperature fusing materiadapted, when melted, vto spreadthrough said perforations andelectrically bridge said high temperature fusing conductors.

9. An electr1c circuit thermostat, comprising a channeled strip andacover strip with interlocked lateral edges forming a continuous lengthcasing, v one of said strips serving as a conductor for an electriccircuit, a thin flat strip of easily fusible conducting materialcoextensivev with said channeled strip, and lying within said,

channel and in electrical contact with said conducting strip, a thinfiat metallic -strip also coextensive With said channeled strip andserving as' a second conductor and entirely surrounded by a sleeve ofcontinuous,

f flexible, insulating fabric lying contiguous to said easily fusiblestrip, said insulating sleeve having perforations therethrough on theside vadjacentsaid easily fusible strip, said fusible material adapted,When melted, to spread through said perforations and electrically bridgesaid circuit'conductors.

prising a channeled strip and a cover strip With interlocked lateraledges forming a continuous length casing, said lateral iianges havingbolt holes therethrough at intervals to provide attaching means for saidcasing, one of said strips serving as a conductor for an electriccircuit, a thin flat` strip of easily fusible conducting materialcoextensive with said channeled strip,` and lying within said channeland in electrical contact With l0. An electric circuit thermostat, com--said conducting strip, a thin flat metallic strip serving as a secondconductor and entlrely surrounded. by a sleeve of continuous to saideasily fusible strip, said insulating sleeve having perforationstherethrough on the side adjacent said easily fusible strip, saidfusible material adapted, when melted, to spread through saidperforations and electrically bridge said circuit conductors.

flexible, insulating fabric lying contiguous 11. An electric, circuitthermostat, lcom- 5 prising a channeled strip and a cover strip forminga continuous' length casing, one of electric circuit, a thin fiat stripof easily l said strips serving as a conductor for an fusible'conducting material coextensive withl said channeled strip and lyingWithin said channel 4and in electrical contact with said conductingstrip, a thin flat metallic strip also coextensive with said channeledstrip and'serving as a second conductor andentirel surrounded by asleeve of continuous, fleXi le, insulating fabric lying contiguous tosaid easily fuslble strip, said insulating sleeve having perforationstherethrough on the side adjacent said easily fusible strip,

v vto spread through said perforations andsaid fusible material adapted,when melted,

electrically bridge said circuit conductors,

said channeled strip having raised surfaces transversely thereof and atintervals'along 1 its. length to retard the-lengthwise spreadin of saidfusible material when melted.

day of November, 1917.

. y JOHN H. DERBY.

.ERNEST S. CLAYTON,

' igned at New York city, N. Y., this 30th I

